Despite decades of research effort directed towards understanding the basic biology, etiology, prevention, and means of treatment of malignant disease, cancer remains one of the most serious health problems for the US population. Over 1.4 million new cancer cases are diagnosed each year and over one half million persons will die as a consequence. Approximately 40% of men and 33% of women in the US will develop cancer by their 85th birthday. The need for this interdisciplinary training program in cancer epidemiology and biostatistics has never been greater. The virtual explosion in recent years of new knowledge regarding the biological mechanisms underlying the development of cancer, particularly at the molecular level and in regard to the role of genetic determinants, continues to accelerate, presenting both new challenges and unprecedented opportunities within the public health sciences field to translate this knowledge from new technologies into significant improvements in incidence and mortality from cancer. The purpose of the University of Washington's long-standing training program in cancer epidemiology and biostatistics is to provide the highest level of training and experience in these closely-related disciplines that will enable the trainee to address this problem through the conduct of high quality cancer research. The program is housed in the Departments of Epidemiology and Biostatistics in the School of Public Health of the University of Washington. All of the predoctoral trainees and most of the postdoctoral trainees have been enrolled in the graduate programs that these departments offer. Much of the training also takes place at our affiliated institution, the Fred Hutchinson Cancer Research Center. For the new award period we propose to train seven predoctoral students (enrolled in the epidemiology or biostatistics PhD program, and four postdoctoral trainees (most within a few years of their doctorate). The Training Grant has been in operation now for 35 years. Of the approximately 160 trainees that have entered through the program, most have had backgrounds in the health professions, science, and/or mathematics. Our program's record has been a good one. With very few exceptions, all positions on the training grant have been filled, and the overwhelming majority of the trainees who began the program have completed it. In addition, nearly all trainees who completed the program have pursued careers in science or public health, and they have produced a large quantity of noteworthy cancer research, both while they were in the training program and afterwards. The past award period has seen a significant increases in the number of trainees from underrepresented minority groups compared to past years. A minor change in this revised application is a new co-Director representing the Biostatistics Department.